The process of changing the sampling rate of a discrete signal to obtain a new discrete representation of the underlying continuous signal is referred to as “sample rate conversion.” Common applications of sample rate conversion include audio/visual (“A/V”) systems and image scaling, for example, where different sampling rates may be used for a variety of historical, engineering, and/or economic reasons. For example, television and film use different sampling rates, as do compact disc (“CD”) audio systems and digital audio tape (“DAT”) systems. Sample rate conversion techniques prevent changes in pitch and speed that might otherwise occur during transfer of recorded material between systems that employ different sampling rates.
Sample rate conversion may also include or be referred to as sampling-frequency conversion, resampling, up sampling, down sampling, interpolation, decimation, upscaling, downscaling; “multi-rate digital signal processing” is sometimes used to refer to systems that incorporate sample rate conversion.
Implementation of an SRC in a parallel scheme involves obtaining the input samples as required by a rate conversion factor at an output clock rate for filter operations in each parallel line. Such an implementation of an SRC also involves obtaining the required coefficients for each parallel line as required by the rate conversion factor.